I was thinking a lot about this point and I changed my oppinion on this a bit. the most realistic (maybe only realistic?) scenario to trade up is, that Spurs pack the Buck's pick and their first rounder to trade up for (at best) 5 spots. if they add some more, they might be able to jump for another spot or two, but that's it.
now I see it a bit different. the most attracting players (like the mentioned Brewer and Green) will still be out of reach, but as often mentioned, there will be a variety of decent (wing) role players, in other words, exactly what the Spurs need.
I was thinking about the other teams needs and expect even more, that those players drop to the area where Spurs have two picks, because (other than Spurs) most teams are well equiped at the wing. thoses teams would pick a potential star SF even if they have a decent player at SF, but not thoses role player typ SFs.
so the board likely will still be full of nice options (Nichols, Byars, McGuire, Tucker, Rush and some more) and in this case I would prefer to be able to pick two players out of this group, or to pick an interesting PG (Shakur, T.Green?) or big (Fazekas?)
so overall I prefer two picks in the area the Spurs currently are over a 23 or 24 pick. if Spurs go "conservative" and would pick for example Tucker and Nichols, this will also be a good solution, since Spurs have to repleace 3 wing players within the next 1 1/2 years and White is not a sure thing to be one of those repleacements.